Hydrangea plant named ‘Agrihydratwaalf’

ABSTRACT

A new and distinct cultivar of  Hydrangea  plant named ‘Agrihydratwaalf’, characterized by its upright and somewhat outwardly spreading plant habit; vigorous growth habit; strong and sturdy stems; freely flowering habit with numerous sterile and fertile flowers per inflorescence; large mophead inflorescences with white-colored flowers with dark red-colored margins; and short production time as a cooling treatment is not required for flower development.

Botanical designation: Hydrangea hybrida.

Cultivar denomination: ‘AGRIHYDRATWAALF’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Hydrangea plant, botanically known as Hydrangea hybrida and hereinafter referred to by the name ‘Agrihydratwaalf’.

The new Hydrangea plant is a product of a planned breeding program conducted by the Inventor in Aalsmeer, The Netherlands. The objective of the breeding program was to create new freely branching Hydrangea plants with strong and sturdy stems, large inflorescences, attractive flower color and not requirement for a cooling treatment for flower development.

The new Hydrangea plant originated from a cross-pollination made by the Inventor on Apr. 20, 2007 in De Kwakel, The Netherlands, of a proprietary selection of Hydrangea hybrida identified as code number 201141-02, not patented, as the female, or seed, parent with a proprietary selection of Hydrangea hybrida identified as code number 201082-01, not patented, as the male, or pollen, parent. The new Hydrangea plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination in a controlled greenhouse environment in Glandorf, Germany on Mar. 15, 2009.

Asexual reproduction of the new Hydrangea plant by vegetative cuttings in a controlled environment in Glandorf, Germany since Mar. 15, 2010 has shown that the unique features of this new Hydrangea plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Hydrangea have not been observed under all possible environmental conditions and cultural practices. The phenotype may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘Agrihydratwaalf’. These characteristics in combination distinguish ‘Agrihydratwaalf’ as a new and distinct Hydrangea plant:

-   -   1. Upright and somewhat outwardly spreading plant habit.     -   2. Vigorous growth habit.     -   3. Strong and sturdy stems.     -   4. Freely flowering habit with numerous sterile and fertile         flowers per inflorescence.     -   5. Large inflorescences with white-colored flowers with dark         red-colored margins.     -   6. Short production time as a cooling treatment is not required         for flower development.

Plants of the new Hydrangea can be compared to plants of the female parent selection. Plants of the new Hydrangea differ from plants of female parent selection primarily in the following characteristics:

-   -   1. Plants of the new Hydrangea have stronger branches than         plants of the female parent selection.     -   2. Plants of the new Hydrangea and the female parent selection         differ in sterile flower color as plants of the female parent         selection have whiter-colored sterile flowers without         red-colored margins.

Plants of the new Hydrangea can be compared to plants of the male parent selection. Plants of the new Hydrangea differ from plants of male parent selection primarily in sterile flower color as plants of the male parent selection have red-colored sterile flowers.

Plants of the new Hydrangea can be compared to plants of the Hydrangea hybrida ‘801’, disclosed in U.S. Plant Pat. No. 16,204. Plants of the new Hydrangea differ from plants of ‘801’ in the following characteristics:

-   -   1. Plants of the new Hydrangea have stronger branches than         plants of ‘801’.     -   2. Plants of the new Hydrangea and ‘801’ differ in sterile         flower color as plants of ‘801’ have white-colored sterile         flowers without red-colored margins.

BRIEF DESCRIPTION OF THE PHOTOGRAPH

The accompanying colored photograph illustrates the unique appearance of the new Hydrangea plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photograph may differ from the color values cited in the detailed botanical description which accurately describe the colors of the new Hydrangea plant. The photograph comprises a side perspective view of a typical flowering plant of ‘Agrihydratwaalf’ grown in a container.

DETAILED BOTANICAL DESCRIPTION

Plants used in the aforementioned photograph and in the following description were grown during the winter in 15-cm containers in a glass-covered greenhouse in De Kwakel, The Netherlands and under environmental conditions and cultural practices which closely approximate commercial Hydrangea production conditions. During the production of the plants, day and night temperatures averaged 17° C. Plants of the new Hydrangea were one year old when the photograph and description were taken. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 1995 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical description: Hydrangea hybrida ‘Agrihydratwaalf’. -   Parentage:     -   -   Female, or seed, parent.—Proprietary selection of Hydrangea             hybrida identified as code number 201141-02, not patented.         -   Male, or pollen, parent.—Proprietary selection of Hydrangea             hybrida identified as code number 201082-01, not patented. -   Propagation:     -   -   Type cutting.—By vegetative cuttings.         -   Time to initiate roots, summer.—About two weeks at             temperatures of 23° C.         -   Time to initiate roots, winter.—About 18 days at             temperatures of 18° C.         -   Time to produce a rooted young plant, summer.—About four             weeks at temperatures of 23° C.         -   Time to produce a rooted young plant, winter.—About five             weeks at temperatures of 18° C.         -   Root description.—Thick; whitish brown in color.         -   Rooting habit.—Freely branching; dense. -   Plant description:     -   -   Plant and growth habit.—Upright to somewhat outwardly             spreading plant habit; rounded in shape; strong and sturdy             stems; rapid growth rate and vigorous growth habit.         -   Plant height.—About 25 cm to 30 cm.         -   Plant diameter or area of spread.—About 35 cm. -   Lateral branch description:     -   -   Branching habit.—Freely branching habit with about six             lateral branches per plant.         -   Length.—About 18 cm to 23 cm.         -   Diameter.—About 5 mm to 7 mm.         -   Internode length.—About 3.5 cm to 5 cm.         -   Stem texture.—Smooth, glabrous.         -   Strength.—Strong and sturdy.         -   Color.—Close to 144B; at the nodes, close to 187A;             lenticels, close to 187A. -   Foliage description:     -   -   Arrangement.—Opposite, simple.         -   Length.—About 10 cm to 12.5 cm.         -   Width.—About 7 cm to 9 cm.         -   Shape.—Ovate.         -   Apex.—Acute.         -   Base.—Obtuse.         -   Margin.—Dentate.         -   Texture, upper surface.—Smooth to rugose, glabrous.         -   Texture, lower surface.—Rugose, glabrous.         -   Venation pattern.—Pinnate.         -   Color.—Developing leaves, upper surface: Close to 147A.             Developing leaves, lower surface: Close to 137C. Fully             expanded leaves, upper surface: Close to 147B; venation,             close to 145B. Fully expanded leaves, lower surface: Close             to 137C; venation, close to 145C.         -   Petiole.—Length: About 2 cm to 3 cm. Diameter: About 4 mm.             Texture, upper and lower surfaces: Smooth, glabrous. Color,             upper and lower surfaces: Close to 145B. -   Flower description:     -   -   Flower type and habit.—Single rounded sterile and             star-shaped fertile flowers arranged on terminal panicles;             panicles globular in shape; flowers face upright to             outwardly.         -   Fragrance.—None detected.         -   Natural flowering season.—Short production time as a cooling             treatment is not required for flower development; continuous             flowering during the summer in Northern Europe.         -   Flower longevity.—Sterile flowers last about four months on             the plant, sterile flowers persistent; fertile flowers last             about four weeks on the plant, fertile flowers not             persistent.         -   Quantity of flowers.—Freely flowering habit; about 80             sterile flowers per panicle and about 30 fertile flowers per             panicle.         -   Panicle height.—About 8 cm to 9 cm.         -   Panicle diameter.—About 12 cm to 14 cm.         -   Sterile flower diameter.—About 3 cm to 3.5 cm.         -   Sterile flower depth (height).—About 8 mm.         -   Fertile flower diameter.—About 5 mm.         -   Fertile flower depth (height).—About 4 mm.         -   Petals, fertile flowers only, sterile flowers without             petals.—Quantity and arrangement: About five in a single             whorl. Length: About 4 mm. Width: About 2 mm. Shape: Ovate.             Apex: Acute. Base: Attenuate. Margin: Entire. Texture, upper             and lower surfaces: Smooth, glabrous. Color: When opening,             upper surface: Close to 145D. When opening, lower surface:             Close to 145B. Fully opened, upper and lower surfaces: Close             to 155B; color becoming closer to 155C with development.         -   Sepals, sterile flowers.—Quantity and arrangement: About             four in a single whorl. Length: About 1.3 cm to 1.5 cm.             Width: About 1.5 cm to 1.7 cm. Shape: Roughly deltoid. Apex:             Obtuse. Base: Cuneate. Margin: Finely crenate; sinuate and             undulate. Texture, upper and lower surfaces: Smooth,             glabrous. Color: When opening and fully opened, upper             surface: Close to 157B; at the margins, close to 178A. When             opening and fully opened, lower surface: Close to 155D.         -   Sepals, fertile flowers.—Quantity and arrangement: About             four in a single whorl. Length: About 3.5 mm. Width: About             2 mm. Shape: Ovate. Apex: Acute. Base: Obtuse. Margin:             Entire. Texture, upper and lower surfaces: Smooth, glabrous.             Color, upper and lower surfaces: Close to 155B.         -   Pedicels, sterile flowers.—Length: About 1.5 cm to 2.5 cm.             Diameter: About 2 mm to 4 mm. Strength: Strong. Texture:             Smooth, glabrous. Color: Close to 157B.         -   Pedicels, fertile flowers.—Length: About 5 mm to 10 mm.             Diameter: About 1.5 mm. Strength: Strong. Texture: Smooth,             glabrous. Color: Close to 157B and 183D.         -   Reproductive organs, fertile flowers only; sterile flowers             without reproductive organs.—Stamens: Quantity per flower:             About eight. Anther shape: Conical. Anther length: About             1 mm. Anther color: Close to 155B. Pollen amount: Abundant.             Pollen color: Close to 155D. Pistils: Pistil quantity per             flower: About three. Pistil length: About 3 mm. Stigma             shape: Oval. Stigma color: Close to 155B. Style length:             About 2 mm to 3 mm. Style color: Close to 155B. Ovary color:             Close to 155B.         -   Seeds.—Length: About 1 mm. Diameter: About 0.2 mm. Color:             Close to 200C. -   Disease/pest resistance: Under commercial production conditions,     plants of the new Hydrangea have not been observed to be resistant     to pathogens or pests common to Hydrangea. -   Temperature tolerance: Plants of the new Hydrangea have been shown     to be tolerant to temperatures ranging from about 3° C. to about 38°     C. 

It is claimed:
 1. A new and distinct Hydrangea plant named ‘Agrihydratwaalf’ as illustrated and described. 